Gas-heating system



Jan. 22, 1929. 1,699,743

J. MACKENZIE GAS HEATING SYSTEM File+d May 22', 1925 2 Sheets-Sheet 1 Jan. 22, 1929. 1,699,743

J. MACKENZIE GAS HEATING SYSTEM Filed May 22, 1925 2 Sheets-Sheet 2 L Jnmm for Joh Macks Hz is Patented JOHN MAGKENZIE, 0F MINNEAPOLIS, MINNESOTA, ASSIGNOR, 0F ONE-HALF T0 WALTER HEYNACHER, GE MINNEAPOLIS, MINNESOTA.

- GAS-HEATING SYSTEM.

My invention relates to improvements in gas heating systems.

An object of the invention is to provide a simple and automatic heating appliance for use in connection with a furnace or other heater, said appliance being adapted to provide for'the eflicient combustion of the usual city gas or other gas supplied forheating purposes. g

A. further object is to supply a gas heating system, asabove, the same including a blower driven by an electric motor for supplying air in admixture with gas at the I an dill

burner and, also, including an electrically actuated valve fitted in the gas line and connected :in the motor circuit, whereby the flow of-gas is arrested upon discontinuance of the supply of air from the blower, as by interruption of the motor circuit.

' Another object is to provide a system of the instant character, wherein the motor circuit is interrupted and completed by an operating mechanism and a cut-off valve in the gas line is opened and closed by said mechanism, said cut-ofi valve being adapted to be opened following the completion of the motor circuit, whereby motor speed may be gained for the supply of air in normal volume prior to the opening of the gas line to the burner.

With the foregoing and other objects in view, which will appear in the following description, the invention resides in the novel combination and arrangement of parts and in the details of construction hereinafter described and claimed.

1n the drawings, Fig. 1'is aplan view of a heating system embodying my invention, parts thereof being shown more or. less diagrammatically; Fig. 2' is a sectional view taken as on the line 2-2 of Fig. 1 and illustrating certain parts of the appliance in elevatlon and other parts thereof diagrammatically and Fig. 3 is anelevational view, broken away in part,-illustrating certain details of the operating mechanism.

In Fig. 1 of the drawing, A designates a furnace or heater of conventional or suit able type such, for example, as is employed in heating dwellings or other buildings. In the fire box of the heater A, 1 place a burner 11 with which a main gas lead 12 is connected. A blower 13, driven by an electrio motor 14, is connected by means of an air lead 15 with the gas lead 12 through a Application filed may at, 1925. Serial m. 32,124.

Y fitting 16, valve 17 18 being respectively fitted in the gas and air leads 12, 15 immediately in advance of the Y fitting 16 to provide for adjusting the fuel mixture of gas and air delivered to the burner 11.

Were combustion at the burner 11 to be maintained without variation or interruption, that part of the appliance described would serve without any addition thereto. It 1s necessary, however, in heating dwellings or other buildings to vary the consumption of fuel at the burner to accord with the various conditions and it has been found that the most efficient practice resides in operating the burner full on to attain the desired temperature and then extinguish the flame at the burner until such time as additional heat is required. A cut-ofi valve. 19 of ordinary pattern, fitted in the gas lead 12, includes a lever 20 for lifting and depressing the valve stem 21, through which stem the valve is correspondingly opened and closed. Said lever 20 is supplied with a weight 22 for lowering the same and has connected thereto a chain 23 for raising said lever against the action of said weight 22. This chain 23 is fastened to an arm 24 on the shaft or prime mover 25 of a suitably driven operating mechanism B of conventional type, which may be actuated by a conventional thermostatic device C located in the heated space. Generally illustrative of such conventional thermostatic devices and of such conventional operating mechanism, without the built in switch members 26 and 27, are the disclosures in Letters Patent of the United States No. 1,162,372, Nov. 30, 1915 to J. C. hiersteter for motor and No. 1,167,890, Jan 11, 1916 to F. S. Denison for electric motor, both assigned to Minneapolis Heat Regulator Co. in the response of the operating mechanism 13 to each actuation of the thermostatic device G, the shaft 25 is turned one-half revolution, the valve 19 being thus opened at a pie-determined minimum temperature in I the heated space and closed at a predetermined maximum temperature therein. Since it is desirable that the operation of the blower 13 be discontinued when the valve 19 is closed, 1 provide, in conjunction with the operating mechanism B, a pair of complementary switch members 26,127, the same being incorporated in the conductor 28 of the motor circuit. The switch members 26,

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27 are brought into contact by the operating mechanism B, through the medium of a cam (Z on shaft 25, or other suitable means, to complete the motor circuit when the valve 19 is opened. This cam 4 provides for the separation of said members 26, 27 by the operating mechanism 13 to interrupt the motor circuit when said valve 19 is closed,

by said mechanism. Although the switch. members 26, 27 and the valve 19 are operated by the mechanism B, it will be understood that there is a delayed action in the opening of said valve following the closing of said switch members. This delayed action may be brought about in any suitiable manner arrangement is important in that it insures the introduction to the, burner 11 of an initial lean mixture 7 rather than an initial rich mixture, the former having the advantage of clean and noiseless ignition as opposed to popping ignition and carbonizing combustion in the latter.

The motor 14, taking its current from the usual power lines, is subject to unpremeditated cessation of operation due to accidental interruptions in the flow of currentthereto. The cessation of operation of the motor 14 and its connected blower 13, when the cut-off valve 19 is open, would result detrimentally in the burning of. pure gas at the burner 11 were it not for a safety valve 29 that is employed in the gas lead 12 in advance of said cut-otl' valve 19. This safety valve 29 has a fulcrumed lever 30 connected with the valve stem 31. A weight 32 on said lever 30 operates to close the valve and an armature core 33 depending from the lever 30 and hanging in a solenoid winding 34 operates to open said valve 29 against the action of said weight. Said solenoid winding 34 being incorporated in the conductor 35-of the motor circuit, it will be understood that the ei'iergization thereof, upon completion of the motor circuit, will result in the attraction of the armature core 38 and the consequent opening of the valve 29 and that the deenergiza tion of said winding, upon the breaking of the motor circuit, will allow the weight 32 to retract the armature core 33' and thereby cause the closing of the valve 29.

Taking off from the main gas lead 12 .at a point in advance of the safety valve 29 and rejoining said lead at a point between the mixing valve 17 and burner 11 is a shunt pipe 36, the same being titted with spaced cut-oft valves 37, 38 and also with a mixer valve 39 interposed between said outotl valves. Branching from the shunt pipe 36 at a point in advance of said assemblage of valves 37', 38 and 39 is a pilot feed pipe 40, the same having a pilot fitting 40 at the tip thereof for the burner 11 and also being provided with a valve 41 for adjusting the flame issuing from said pilot fitting 10. Gas flowing from the main gas lead 12 into the shunt pipe 36 and thence into the pilot teed pipe 10 provides for a continuous pilot flame at the burner 11 regardless of the setting of the valves 17, 19 and 29 in the main gas lead. Under ordinary circumstances the valves 87, 38 in the shunt pipe 36 are closed, but under emergency, when the blower 13 cannot be operated, the valves 17, 18 in the gas and air leads 12, 15 are closed and said valves 37, 38 opened to permit of combustion at the burner 11 of gas mixed with air at a'tu'iospheric pressure.

In the operation of the appliance, the safety valve 29 opens upon completion of the motor circuit by the operating mechanism 13 and closes upon the interruption of said circuit by said mechanism or otherwise. Opening after the motor circuit has been completed by the operating mechanism B, the cut-oi? valve 19 holds back the flow of gas to the burner 11 until air passes in normal volume from the blower 18 to said burner.

Changes in the specific form of my invention, as herein disclosed, may be made Within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Lctters Patent is:

1. The combination with a heater of a burner therein, a gas lead connected with said burner, two cut-oft valves fitted in said gas lead, one a mechanically operated valve and one an electrically operated valve, a blower for delivering air into the gas lead at a point between said burner and valves, an electric motor for driving said blower, an electric circuit common to the motor and the electrically operated valve, operating mechanism acting to break and complete said circuit and to correspondingly close and open said mechanically actuated valve, said electrically operated valve being adapted automatically to close upon cessation of the flow of current through said circuit, as through the operation of said mechanism or otherwise, the opening of said mechanically operated valve, upon the completion of said circuit by said operating mechanism, being attended with delay to allow for the pick up of speed in the motor prior to the opening of said gas lead by said valve.

2. The combination with a heater of a burner therein, a gas lead connectedwith said burner, a valve in said gas lead, a blower, an air lead for conducting air from the blowerto the gas lead at a point between IOU Val

said valve and burner, a valve in said air lead, a shunt pipe for conveying gas to the burner, said pipe being connected with the gas lead at a point in advance of the valve therein, spaced cut-ofi' valves fitted in said shunt pipe, and an air admission valve fitted in said pipe between said cut-oflf valves.

3. The combination with a heater of a burner therein, a gas lead connected with said burner, a valve in said gas lead, a blower, an air lead for conducting air from the blower to the gas lead at a point between said valve and burner, a valve in said air lead, a shunt pipe for conveying gas to the burner, said pipe being connected with the gas lead at a point in advance of the valve therein, spaced cut-off valves fitted in said shunt pipe, and an air admission valve fitted in said pipe between said cut-off valves, and a pilot feed pipe associated with said burner and connected with the shunt pipe at a point in advance of the first cut-off valve in said shunt pipe.

4. The combination with a heater of a burner therein, a gas lead connected with said burner, a cut-off valve fitted in said gas lead, a blower for delivering air into the gas lead at a point between said valve and burner, an electric motor for driving said blower, said motor having an electric circuit therefor including a switch for making and breaking said circuit, an operating mechanismcommon to said switch and valve, a thermostatic device responsive to temperatures in the heated space, said device being adapted to actuate the operating mechanism, said mechanism having an independent source of power and comprising promptly operative means for closing the motor circuit and delayed operative means for open ing the gas valve, allin one operation, said means serving also to close the valve and open the switch in another operation.

5. The combination with a heater of a burner therein, a. gas lead connected with said burner, a cut-off valve fitted in said gas lead, a blower for delivering air into the gas lead at a point between said valve and burner, an electric motor for driving said blower, said motor having an electric circuit therefor including a switch for making and breaking said circuit, an operating mechanism common to said switch and valve, a thermostatic device responsive to-temperatures in the heated space, said thermostatic device being adapted to actuate the operating mechanism, said mechanism having an independent source of power and comprising promptly. operative means for closing the motor circuit and delayed operative means for opening the gas valve, all in one operation, said means serving also to close the valve and open the switch in another operation, and means separate from the above mentioned, means for shutting ottthe gas supply when the motor circuit is interrupted.

6. The combination with a heater of a burner therein, a gas lead connected with said burner, a valve in said gas lead, a blower, an air lead for conducting air from the blower to the gas lead at a point between said valve and burner, acut-off valve in said air lead, a shunt pipe for conveying gas to said burner connected with the gas main at a. point in advance of said valve therein, and means for supplying air to the burner in conjunction with said shunt pipe.

In testimony whereof, I have signedmy name to this specification.

JOHN MACKENZIE. 

